Question

what is particle interaction...?

Answer 1

Gluons. Gluons are the exchange particlesfor the color force between quarks, analogous to the exchange of photons in the electromagnetic force between two charged particles. The gluon can be considered to be the fundamental exchange particle underlying the strong interactionbetween protons and neutrons in a nucleus.

Answer 2

Particle Interactions

There are four fundamental forces;

gravity

electromagnetic force

strong nuclear force

weak nuclear force

To explain the forces between particles we use the concept of exchange particles orbosons.

Gravity – gravitons

All particles with mass attract each other with the force of gravity, the mechanism by which particles attract each other is through the exchange of particles calledgravitons (as yet undetected).

Electromagnetic force – virtual photons

The virtual photon is the exchange particle (or boson) which carries theelectromagnetic force between charged particles. Particles with electric charges can either attract or repel each other by exchanging particles called virtual photons.

Strong nuclear force – gluons

Gluons are the exchange particles involved in the strong nuclear force interaction.

Weak nuclear force – W+, W- bosons

W and Z  bosons ( in A-level we just need the W+ and W– bosons) are the exchange particles  involved in the weak nuclear force interaction.

The weak force acts within the  nucleus, quarks and leptons excerpt forces on each other by exchanging bosons. The weak nuclear force is very weak and acts over a very small distance.